powerpc ioremap_prot
This adds ioremap_prot and pte_pgprot() so that one can extract protection
bits from a PTE and use them to ioremap_prot() (in order to support ptrace
of VM_IO | VM_PFNMAP as per Rik's patch).
This moves a couple of flag checks around in the ioremap implementations
of arch/powerpc. There's a side effect of allowing non-cacheable and
non-guarded mappings on ppc32 which before would always have _PAGE_GUARDED
set whenever _PAGE_NO_CACHE is.
(standard ioremap will still set _PAGE_GUARDED, but ioremap_prot will be
capable of setting such a non guarded mapping).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Rik van Riel <riel@redhat.com>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 4d7e2ba..a487671 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -111,6 +111,7 @@
select HAVE_DYNAMIC_FTRACE
select HAVE_FTRACE
select HAVE_IDE
+ select HAVE_IOREMAP_PROT
select HAVE_KPROBES
select HAVE_ARCH_KGDB
select HAVE_KRETPROBES
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index c758407..2001abd 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -145,13 +145,20 @@
void __iomem *
ioremap(phys_addr_t addr, unsigned long size)
{
- return __ioremap(addr, size, _PAGE_NO_CACHE);
+ return __ioremap(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED);
}
EXPORT_SYMBOL(ioremap);
void __iomem *
ioremap_flags(phys_addr_t addr, unsigned long size, unsigned long flags)
{
+ /* writeable implies dirty for kernel addresses */
+ if (flags & _PAGE_RW)
+ flags |= _PAGE_DIRTY | _PAGE_HWWRITE;
+
+ /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
+ flags &= ~(_PAGE_USER | _PAGE_EXEC | _PAGE_HWEXEC);
+
return __ioremap(addr, size, flags);
}
EXPORT_SYMBOL(ioremap_flags);
@@ -163,6 +170,14 @@
phys_addr_t p;
int err;
+ /* Make sure we have the base flags */
+ if ((flags & _PAGE_PRESENT) == 0)
+ flags |= _PAGE_KERNEL;
+
+ /* Non-cacheable page cannot be coherent */
+ if (flags & _PAGE_NO_CACHE)
+ flags &= ~_PAGE_COHERENT;
+
/*
* Choose an address to map it to.
* Once the vmalloc system is running, we use it.
@@ -219,11 +234,6 @@
v = (ioremap_bot -= size);
}
- if ((flags & _PAGE_PRESENT) == 0)
- flags |= _PAGE_KERNEL;
- if (flags & _PAGE_NO_CACHE)
- flags |= _PAGE_GUARDED;
-
/*
* Should check if it is a candidate for a BAT mapping
*/
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 3ef0ad2..365e61a 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -107,9 +107,18 @@
{
unsigned long i;
+ /* Make sure we have the base flags */
if ((flags & _PAGE_PRESENT) == 0)
flags |= pgprot_val(PAGE_KERNEL);
+ /* Non-cacheable page cannot be coherent */
+ if (flags & _PAGE_NO_CACHE)
+ flags &= ~_PAGE_COHERENT;
+
+ /* We don't support the 4K PFN hack with ioremap */
+ if (flags & _PAGE_4K_PFN)
+ return NULL;
+
WARN_ON(pa & ~PAGE_MASK);
WARN_ON(((unsigned long)ea) & ~PAGE_MASK);
WARN_ON(size & ~PAGE_MASK);
@@ -190,6 +199,13 @@
void __iomem * ioremap_flags(phys_addr_t addr, unsigned long size,
unsigned long flags)
{
+ /* writeable implies dirty for kernel addresses */
+ if (flags & _PAGE_RW)
+ flags |= _PAGE_DIRTY;
+
+ /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
+ flags &= ~(_PAGE_USER | _PAGE_EXEC);
+
if (ppc_md.ioremap)
return ppc_md.ioremap(addr, size, flags);
return __ioremap(addr, size, flags);
diff --git a/include/asm-powerpc/io.h b/include/asm-powerpc/io.h
index 8b62782..77c7fa0 100644
--- a/include/asm-powerpc/io.h
+++ b/include/asm-powerpc/io.h
@@ -617,7 +617,8 @@
* and can be hooked by the platform via ppc_md
*
* * ioremap_flags allows to specify the page flags as an argument and can
- * also be hooked by the platform via ppc_md
+ * also be hooked by the platform via ppc_md. ioremap_prot is the exact
+ * same thing as ioremap_flags.
*
* * ioremap_nocache is identical to ioremap
*
@@ -639,6 +640,8 @@
extern void __iomem *ioremap_flags(phys_addr_t address, unsigned long size,
unsigned long flags);
#define ioremap_nocache(addr, size) ioremap((addr), (size))
+#define ioremap_prot(addr, size, prot) ioremap_flags((addr), (size), (prot))
+
extern void iounmap(volatile void __iomem *addr);
extern void __iomem *__ioremap(phys_addr_t, unsigned long size,
diff --git a/include/asm-powerpc/pgtable-4k.h b/include/asm-powerpc/pgtable-4k.h
index fd2090d..c9601df 100644
--- a/include/asm-powerpc/pgtable-4k.h
+++ b/include/asm-powerpc/pgtable-4k.h
@@ -51,6 +51,9 @@
#define _PAGE_HPTEFLAGS (_PAGE_BUSY | _PAGE_HASHPTE | \
_PAGE_SECONDARY | _PAGE_GROUP_IX)
+/* There is no 4K PFN hack on 4K pages */
+#define _PAGE_4K_PFN 0
+
/* PAGE_MASK gives the right answer below, but only by accident */
/* It should be preserving the high 48 bits and then specifically */
/* preserving _PAGE_SECONDARY | _PAGE_GROUP_IX */
diff --git a/include/asm-powerpc/pgtable-ppc32.h b/include/asm-powerpc/pgtable-ppc32.h
index 3a96d00..bdbab72 100644
--- a/include/asm-powerpc/pgtable-ppc32.h
+++ b/include/asm-powerpc/pgtable-ppc32.h
@@ -395,6 +395,12 @@
#ifndef _PAGE_EXEC
#define _PAGE_EXEC 0
#endif
+#ifndef _PAGE_ENDIAN
+#define _PAGE_ENDIAN 0
+#endif
+#ifndef _PAGE_COHERENT
+#define _PAGE_COHERENT 0
+#endif
#ifndef _PMD_PRESENT_MASK
#define _PMD_PRESENT_MASK _PMD_PRESENT
#endif
@@ -405,6 +411,12 @@
#define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
+
+#define PAGE_PROT_BITS __pgprot(_PAGE_GUARDED | _PAGE_COHERENT | _PAGE_NO_CACHE | \
+ _PAGE_WRITETHRU | _PAGE_ENDIAN | \
+ _PAGE_USER | _PAGE_ACCESSED | \
+ _PAGE_RW | _PAGE_HWWRITE | _PAGE_DIRTY | \
+ _PAGE_EXEC | _PAGE_HWEXEC)
/*
* Note: the _PAGE_COHERENT bit automatically gets set in the hardware
* PTE if CONFIG_SMP is defined (hash_page does this); there is no need
@@ -538,6 +550,10 @@
pte_val(pte) |= _PAGE_ACCESSED; return pte; }
static inline pte_t pte_mkspecial(pte_t pte) {
return pte; }
+static inline unsigned long pte_pgprot(pte_t pte)
+{
+ return __pgprot(pte_val(pte)) & PAGE_PROT_BITS;
+}
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
{
diff --git a/include/asm-powerpc/pgtable-ppc64.h b/include/asm-powerpc/pgtable-ppc64.h
index ab98a9c..ba80003 100644
--- a/include/asm-powerpc/pgtable-ppc64.h
+++ b/include/asm-powerpc/pgtable-ppc64.h
@@ -117,6 +117,10 @@
#define PAGE_AGP __pgprot(_PAGE_BASE | _PAGE_WRENABLE | _PAGE_NO_CACHE)
#define HAVE_PAGE_AGP
+#define PAGE_PROT_BITS __pgprot(_PAGE_GUARDED | _PAGE_COHERENT | \
+ _PAGE_NO_CACHE | _PAGE_WRITETHRU | \
+ _PAGE_4K_PFN | _PAGE_RW | _PAGE_USER | \
+ _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_EXEC)
/* PTEIDX nibble */
#define _PTEIDX_SECONDARY 0x8
#define _PTEIDX_GROUP_IX 0x7
@@ -262,6 +266,10 @@
return pte; }
static inline pte_t pte_mkspecial(pte_t pte) {
return pte; }
+static inline unsigned long pte_pgprot(pte_t pte)
+{
+ return __pgprot(pte_val(pte)) & PAGE_PROT_BITS;
+}
/* Atomic PTE updates */
static inline unsigned long pte_update(struct mm_struct *mm,
